automatic replies from specific exchange user denied

[ITSeksjonen_FFK]

i keep getting 554 5.7.1 when automatic replies are beeing sent to external users from a specific adresss... all other automatic replies from others goes through. regular emails from this address also works.

the smarthost (fortimail) keeps denying.

things ive tried:

[ul]

added this adress to the antispam safelist

checked sender reputation- wich were fine

allowed (legacy) out of office and automatic replies on the exchange hubtransport - remote domains.[/ul]

is there any way i can make this work? i all out of options now... 

-S